Anodal transcranial direct-current stimulation and non-verbal intelligence in autism spectrum disorder: A randomized controlled trial.

AIM: To understand the impact of anodal transcranial direct-current stimulation (tDCS) on non-verbal intelligence in high-functioning young adults with autism spectrum disorder (ASD). METHOD: Thirty individuals with ASD were randomly divided into three groups receiving 2 mA, 20 minutes daily anodal tDCS for 10 sessions. Group A received 10 sham tDCS sessions, group B five real followed by five sham sessions, and group C received 10 real tDCS sessions. The total score of non-verbal intelligence was measured using the Test of Nonverbal Intelligence, Fourth Edition. The left dorsolateral prefrontal cortex (LDLPFC) was targeted using the International 10-20 electroencephalography system, and concurrent cognitive training was avoided. RESULTS: Group C demonstrated a mean difference of 4.10 (95% confidence interval 1.41-6.79; p = 0.005) in Test of Nonverbal Intelligence scores compared with group A, with an effect size of 0.47. No significant differences were observed between groups A and B (p = 0.296), or between groups B and C (p = 0.140). INTERPRETATION: Ten sessions of anodal tDCS to the LDLPFC led to improved non-verbal intelligence among individuals with ASD. These results emphasize the potential of tDCS as a discrete method for boosting cognitive abilities in the high-functioning population with ASD. Future studies with larger groups of participants and extended observation periods are necessary to validate these findings.

Breathing meditation by medical students at Khon Kaen University: effect on psychiatric symptoms, memory, intelligence and academic achievement.

OBJECTIVE: To examine the short-term effects on fifth-year medical students of a 4-week, breathing meditation-based, stress reduction intervention on psychiatric symptoms, memory function, intelligence, and academic achievement. MATERIALS AND METHOD: Using a randomized control trial, the meditation group practiced every 8.00 to 8.20 a.m. before beginning daily learning schedule. Meditation emphasized mindful awareness of the breath during inhaling and exhaling. The control group went about their normal activities in the other room. The psychiatric symptoms were measured using the Symptom Checklist-90 (SCL-90), the memory used the Wechsler Memory Scale-I (WMS-I), the intelligence used the Raven's Advanced Progressive Matrices (APM), and the academic achievement used psychiatry course MCQ examination score. Analysis was done using Ancova statistic. RESULTS: Fifty-eight volunteer medical students during their psychiatry rotation between June 2008 and May 2009, were randomized into either in the meditation (n = 30) or the control (non-meditation) (n = 28) group. There was no significant difference between the groups in their respective SCL-90, WMS-I, APM, and psychiatry course MCQ examination score. CONCLUSION: Among normal, intelligent, mentally healthy persons, short-term breathing meditation practice will not likely change psychiatric symptoms, memory function, intellectual performance, and academic achievement.